Tool



Feb. 6, 1951 D. s. RITCHIE TOOL Filed July 21, 1945 Ila F761 3 7 FIG. 4

A f @3 M0 29 Fig, Irzvrntor I DAYTON s. R/TGl-IIE ttoneys Patented Feb. 6, 1951 UNITED STATES PATENT OFFICE I TOOL Dayton S. Ritchie, Lincolnton, N. 0. Application July 21, 1945, Serial No. 606,309

1 Claim. 1

This invention relates to a tool, and more particularly to a measuring tool.

A primary object of this invention is the provision of an improved measuring tool, which may serve as a straight edge for a rule, and provided with an extensible portion which may be used for additional measurements, either to supplement the length of the initial rule, or for supplementary measurements on a relatively small scale, or as a depth gauge, or the like.

A further object of the invention is the provision of such a device which is particularly adapted for the use of artisans, such as model makers, machinists, electrical workers, students, and others.

A still further object of the invention is the provision of means comprising apertures in either end thereof, permitting the insertion of suitable points whereby the device may be utilized to scribe circles.

Still another object is the provision of improved means for varying the relative position in the inner rule with respect to the casing, in such manner as to provide relatively fine adjustments thereof.

A still further object is the provision of such a device which will be sturdy and durable in construction, reliable and efficient in operation, and relatively simple and inexpensive to manufacture and assemble.

Other objects reside in the combinations of elements, arrangements of parts, and features of construction, all as will be more fully pointed out hereinafter and shown in the accompanying drawing wherein there is disclosed a preferred embodiment of this inventive concept.

In the drawings, wherein like reference characters refer to like parts throughout the several views:

Figure 1 is a perspective view of one form of device embodying features of the instant invention,

Figure 2 is a longitudinal sectional view taken substantially along the center line of the device disclosed in Figure 1,

Figure 3 is an end elevational view of the device as viewed from the left in Figures 1 and 2,

Figure 4 is an end elevational view of the device asviewed in the opposite direction,

Figure 5 is a sectional view taken substantially along the lines 5-5 of Figure 2, and

Figure 6 is an enlarged perspective view of a constructional detail.

Having reference now to the drawings, there is generally indicated at In a casin of any desired material, such as metal, plastic, or the like, of polygonal, preferably rectangular, crosssection. In the illustrative embodiment shown, the four sides of the casing IE! are provided with graduations H to any desired scale, as, for example, the markings on two sides may be in graduations of an eighth of an inch, as shown at i I, while the markings on the other two sides may be in graduations of sixteenths of an inch, as shown at II.

Obviously, if desired, other scales may be used, as for example, two sides of the device may he graduated in accordance with the metric system of measurement.

The casing 10 has a cylindrical bore therein, within which is contained a helix I 2 including a helical groove It. The upper extremity of the helix I2 is provided with a collar M, as best shown in Figure 2, rotatably resting on a shoulder Ila at the socketed end of easing l0. Beyond collar l4 helix l2 terminated in a reduced cylindrical extension Ma surrounding which is a bushing A, beyond which the extremity lea extends. Bushing A is suitably pinned to casing It} as by pins [2a. As best shown in Figure 3, one end of the casing is provided with a closure iii having a rectangular slot l'i therein, through which is adapted to extend the extremity of a rule it, suitably graduated as at E9, in conformity with the graduations or calibrations on the exterior of the casing I0, and terminates, at its inner end, as best shown in Figure 6, in a cylindrical traveller 20 provided with aligned projections 2|, spaced longitudinally at a distance substantially equal to the spacing between the grooves l3 in the helix l2. The outer extremity of extension Ma is pinned as at 220, to knurled cap 22, positioned exteriorly of the end of casing 10.

The cap 22 terminates in a frusto-conical portion 23, from which extends a cylindrical portion 2 3 having a bore 25 therethrough. A small aperture or hole 26 extends through the end of the rule 58.

As best shown in Figure l, the upper extremity of the casing 50 merges into a circular portion 2'! adapted to merge smoothly into the contours of I the knurled cap 22.

From the foregoing, the operation of the device should now be readily understandable. The casing It may be used for ordinary linear measurements, and when additional measurements are desired, the rule It may be moved out of the casing through the slot ll to any desired extent, and additional readings taken ther on as desired, It

3 will be readily understood that rotation of the knurled nut 22 causes corresponding rotation of the helix i2, which, through the prongs 2?, occasions linear movement of the traveller 2%, which; in turn, through the engagement of the spaces H with the pins 2!, causes the rule i8 through the traveller 28 to move in a linea direction into and out of the casing iil as desired.

When it is desired to scribe a circle with the device, it shouldbe readily understandable that a pin may be passed through either the hole 26 or 25, and a lead or similar marker through the opposite hole, and the circle scribed. Obviously, the radius of the circle may be varied in accordance with the relative position of the rule in or out of the casing.

From the foregoing, it will now ice 'seen that there is herein provided a device accomplishing all of the objects of this invention, and others, including many advantages of great practical utility and commercial importance.

As manyembodiments may be made of this inventive concept, and as many modifications may be made in the embodiment hereinbefore shown and described, itis to be understood that all matter herein is to be interpreted merely as illustrative and not in a'limiting sense.

A measuring device comprising a flat sided housing having aligned therein, a slot and bore, graduations on the exterior surfaces of said housing, a rule slidably received in said slot and said bore, means for adjustably sliding said rule, said means including a sleeve with helical grooves and disposed in said bore, a slide member rigidly secured to said rule, protuberances on said slide member operatively engaging the grooves of said sleeve, means rotatably journaled on said housing for rotating said sleeve, and means for preventing rotational movement of said slide memher.

DAYTON S. RITCHIE.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 481,515 raut Ang.'23,1892 1,422,984: Johnson July 18,1922 1,488,482 Eckman Apr. .1, 1924 1,806,849 Gelardi May 26, 1931 1,922,758 Christopherson Aug. 15, 1933 2,213,026 Hoffman Aug.'2'7, 1940 

